Poor customer service

My discovery bank app shows that I qualify for 34% cashback on Healthy Foods, but with my December cashback, I realized there is something very wrong! I am only receiving 11%!! I am not sure when the issue started- I have asked too many times to give me my qualifying spend for the previous months so I can determine since when I have received below my %cashback - each time met with a different excuse - why do you want to hide this information?? I've been told that it will be emailed to me - also to no avail. Wanting this massive issue to be resolved, I have been speaking to a number of support consultants, but it is clear they are unable to assist me as the matter is ''very complicated''. Each gave me a different reference number to the *****y- only for the next consultant to tell me to wait another 5 working days for feedback. I no longer trust Discovery. There is no transparency. It is infuriating as I moved everything incl medical aid, bank, car insurance, and home insurance to Discovery. If this matter is not resolved by the end of January I have no other option but to cancel all my discovery products.